When using a third party service for research, security isn't the only thing to worry about.  You may be giving away your intellectual property to the service provider.  Amy Bruckman and Casey Fiesler have analyzed the terms of service for 30 of the top online services.

"If you're like a majority of web users, it's easy to skim or skip the Terms of Service (ToS) agreement. How do we know what we're reading, much less agreeing to? It turns out, you may be giving away more than you think."

Copyright Terms in Online Creative Communities, Amy Bruckman and Casey Fiesler (graphic).